Michigan State Police Lieutenant Mike Shaw said several people were arrested.

“During the execution of the search warrants, so far we seized over 500 marijuana plants, a large quantity of processed marijuana, and several weapons from the raids,” Shaw said. “This operation was all related . This was different warehouses where marijuana was grown, different houses where there was stash houses where they kept the marijuana and different places where they processed it.”

Twenty two buildings were raided in all, and Shaw said one of the homes that was to be part of the raid was the home in Ypsilanti Township that exploded on Sunday.

He said the fire marshal will have to determine the cause, but says there was a marijuana processing operation there and butane was being used to make marijuana wax.

Those arrested are expected to be arraigned Tuesday. Their names will be released at that time.

The ATF, FBI and multiple city and county law enforcement agencies assisted in what Shaw says was a seven month investigation.